Automatic prime mover dynamoelectric plant



y 1934- J. M DRABELLE 1,965,371

AUTOMATIC PRIME MOVER DYNAMO ELECTRIC PLANT Filed Feb. 4, 1930 PatentedJuly 3, 1934 UNITED STATES AUTOMATIC PRIME MOVER DYNAMO= ELECTRIC PLANTJohn M. Drabelle, Cedar Rapids, Iowa, assiglior to General ElectricCompany, a corporation of New York Application February 4.

1930, Serial No. 425,889

Claims. (Cl. 290-30) My invention relates to automatic prime moverdynamo electric plants and its object is to provide an improvedarrangement for automatically placing in operation an internalcombustion engine- Q driven generator and particularly 2. Diesel enginedriven generator. Q

Many small towns and-communities receive electric power from a singlepower line which may be supplied with electric power by a sourcesituated many miles away.- In order to maintain continuity of service,in case the power line or the source connected thereto fails, it isdesirable to have available an auxiliary source of current which may beused while the main source of supply is not available. It is essential,however, that this auxiliary source should be one which is inexpensiveto install and maintain, which can be easily and quickly placed inoperation when it is necessary to operate it, and whose operation can bedepended upon under all conditions of Weather. In accordance with thepreferred embodiment of my invention, I accomplish these results by providing a Diesel engine driven generator, and means for automaticallystarting the Diesel. en gins and connecting the generator to the dis:tributlon system in response to a predetermined voltage failure of thenormal supply circuit for the distribution system.

My invention will be better understood from the following descriptionwhen taken in corn cetion with the accompanying drawing, the singlefigure of which is a diagrammatic representation. of a control systemfor a Diesel engine driven generator, and its scope will be pointed outin the appended claims.

Referring to the accompanying drawing, 1 represents an alternatingcurrent distribution circuit which is normally connected by means of asuitable switch 2 to an alternating current supply circult 3. The switchwhich may he of any suitable'type, examples of which are well known inthe art, ,is shown as a latched in circuit breaker which is held in itsclosed position by a latch a and which is arranged tobe opened inresponse to the energization of a trip coil 5.

In order that thedistribution circuit 1 may be supplied with currentwhen the supply circuit 3 fails, I provide an internal combustion enginedriven dynamo electric plant 6 which is arranged. to bestarted andconnected automatically to the distribution circuit 1 when the voltageof the supply circuit 3 remains below a predetermined value for apredetermined time. As shown, the dynamo electric plant 6 includes 9.Diesel engine '7 direct connected to an alternating current generatorcwhich is arranged to be connected across the distribution circuit 1 bymeans or a suitable circuit breaker 9.

The Diesel engine '7 may beof any suitable constructlon, examples of.which are well known in the art. Preferably, it is a multi+cylinderengine. Any suitable starting arrangement may also be provided. In thearrangement shown in the drawing, it is assumed that the engine isstarted by admitting compressed air from a suitable reservoir 10 to oneor more cylinders of the. engine. This is one of the well knownarrangements for starting a Diesel engine. The supply of air pressurefrom the reservoir 10 to the engine 7 is controlled by means of asuitable valve 11 which is arranged to be opened by means of a nagnet 13when it is energized.

The supply of fuel from. a fuel. tank 15 to the engine 7 is controlledby means of a suitable con trol valve 16 which is arranged to be openedby means of a magnet 1'? when it is energized. In order that the enginemay be primed beficre start-- mg, I provide a suitable primer 18 whichhas an operating winding ill. The engine I is water cooled and thesupply of water to the cooling sysso tern is controlled by a suitablevalve 26 which is arranged to be opened by a magnet 21 when it isenergized. A suitable water flow indicator 22, ex amples of which arewell known in the art, is pro vlded withcontacts 23 which 'are arrangedto be $5 closed when the cooling water is flowing through the coolingsystem of the engine.

With 'the arrangement shown. the engine is started by first opening thevalves 16 and t l, then operating the primer l8 several times and thento opening the valve 11 to admit compressed air to oneor more of theengine cylinders. After the engine starts, the valve ll is closed toshut oil? the supply of compressed air to the engine cylinders andthereby render the starting means inopera till tive.

In order that the various auxiliary devices associated with the engine 7may be operated automatically in the proper sequence to start theengins, I provide a motor operated controller 25 me which includes adriving motor 26 and a plurality of spaced movable contacts which arerespectively arranged to engage stationary contacts so as to completethe variousbontrol circuits in the proper sequence.

As shown in the drawing", the automatic starting of the dynamo electricplant 6 is eilfected in response to the operation of a time delayvoltage relay 27 which is responsive to the voltage of the s pplycircuit 3. When the voltage of the supply will circuit 3 decreases belowa predetermined value and remains below this predetermined value for apredetermined length of time, the relay 2'? effects the energization ofa master relay 28 which, in turn, effects theenergization of a controlrelay 29 to complete an energizing circuit for the controller motor 26.The controller is then operated to efiect the operation of the fuelvalve 16 and the water valve 20 associated with the engine 7 after whichthe original energizing circuit for the control relay 29 is opened. Assoon as the cooling water for the engine 7 begins to flow through thecooling system of the engine '7, the water flow indicator 22 completesan energizing circuit for the control relay 29 to restart the controller25. The controller 25 then efiects successively the operation of theprimer 18 a plurality of times and then the opening of the air valve 11after which the energizing circuit of the control relay 29 is opened tostop the controller until the engine speed reaches a predeterminedvalue. As soon as the engine starts and its speed increases above apredetermined value, a suitable speed responsive device 30 completes anenergizing circuit for the control relay 29 to restart the controllerwhich then eiiects the energization of the trip coil 5 of the circuitbreaker 2 to disconnect the deenergized supply circuit 3 from thedistribution circuit 1 and then effects the ener gization of the controlrelay 31 which, in turn, completes an ener izing circuit for the closingcoil 32 of the circuit breaker 9 so that the unexcited generator 8 isconnected across the distribution circuit 1. The closing of the circuitbreaker 9 completes a circuit for a field contactor 33 which, whenclosed, connects the field winding of the generator 8 across a suitablesource or" direct current such as a direct connected exciter 34 so thatthe load circuit is again energized.

In. case the engine fails to start within a predetermined time, Iprovide an arrangement whereby the controller 25 is moved to its normalshutdown positions if the engine speed does not ,build up to a value toeffect the operation of the speed responsive means 30 within apredetermined time after the air valve 11 is opened to start the engine.This arrangement includes a time relay 36 which is energized when theoperating magnet 13 of the air valve 11 is energized and which, whenenergized for a predetermined length of time, efiects the deenergizationof the master relay 28. The master relay 28, when deenergized, effectsthe completion of a circuit for the motor 26 to return the controller 25to its normal shutdown positions. If the voltage of the normal supplycircuit 3 is still below a predetermined value when the controller 25reaches its normal shutdown positions, the original energizing circuitof the master relay 28 again is completed to effect the operation of thecontroller 25 to attempt another starting of the engine. In order tolimit the number of times the controller 25 can be operated within apredetermined time to effect the starting of the engine, I provide anotching relay 37 which is so connected to the controller 25 that it isenergized once during each revolution of the controller. If thecontroller 25 makes a predetermined number of revolutions within apredetermined time, the relay 3'? is arranged to open permanently itscontacts 38 which are in the circuit of the master relay 28 so that therelay 28 remains deenergized independently of the voltage of the supplycircuit 3 when the controller 25 subsequently reaches its normalshutdown positions.

39 represents a manually controlled switch which is so connected thatwhen it is open it effects the shutting down of the prime'mover plant 6if it is in operation and prevents the plant from being started inresponse to the voltage of the supply circuit when the plant is shutdown.

The operation of the system shown in the drawing is as follows: When thesupply circuit 3 is energized and is connected to the load circuit l bythe circuit breaker 2 and the prime mover plant 6 is shut down, thevarious control devices are in the positions shown in the drawing.

Let it now be assumed that the voltage of the supply circuit 3 decreasesbelow a predetermined value so that the voltage relay 2'? becomesdeenergized. If the supply circuit voltage remains below thispredetermined value for a predetermined length of time, relay 2? closesits contacts ll) and completes an energizing circuit for the masterrelay 28. This circuit is from one side of a suitable control circuitthrough the stationary contacts a and 7' and cooperating movablecontacts of the controller 25, contacts 40 of the voltage relay 27,control switch 39, winding oi relay 28, contacts 38 of notching relay3'7, contacts 41 of relay 36 to the other side of the control circuit.Relay 28 by closing its contacts 43 completes, through the contacts aand c of the controller 25, an energizing circuit ror the control relay29. The control relay 29 by closing its contacts a completes anenergizing circuit for the controller motor 26 so that the controller 25iii moved out of its normal shut down positions.

Shortly after the controller leaves its normal shut down position, itsmovable contacts effect the disconnection of the stationary contact 7"from the stationary contact a and the connection or" the stationarycontacts 2), f and is to the stationary contact a. The connection of thestationary contact b to the stationary contact a of the controller 25completes a locking circuit for the winding of the relay 28 so that thisrelay remains energized after the stationary contact 9' of thecontroller 25 is disconnected from the stationary contact a. Thislocking circuit is from one side of the control circuit through thecontacts a and b of the controller 25, contacts 42 of the relay 28,contacts 40 of the voltage rei lay 27, control switch 39, winding ofrelay 28, contacts 38 of notching relay 37, contacts 41 of relay 36 tothe other side of the control circuit.

The connection of the contact f to the contact a of the controller 25,completes the circuits for the operating magnets 17 and 21 of the fuelvalve 16 and the water valve 20 respectively. The circuits of thesemagnets also include the contacts 45 of the master relay 28. As soon asthe cooling water starts to flow through the cooling system of theengine '7, the water flow indicator 22 closes its contacts 23 so thatwhen the controller 25 reaches its position aa an energizing circuit iscompleted for the control relay 29.

The connection of the contact is to the contact a of the controller 25completes an energizing circuit for the notching relay 37 so that itsmovable arm is moved forward a predetermined distance but not far enoughto effect the .1.-

opening of the relay contacts 38.

When the controller 25 reaches its position cm, the above traced circuitfor the control relay 29 through the contacts a and c of the contro l r25 is opened. If, however, the cooling water is flowing through thecooling system of the engine 7, the contacts 23 of the water flowindicator 22 completes through the contacts a and d of the controller 25and the contacts 43 of the master relay 28 an energizing circuit for thecontrol relay 29 to eifect the movement of the controller from itsposition so to its position bb. Shortly after the controller moves outof its position no, the above traced circuit of the control relay 29through the contacts a and c of the controller 25 is completed to eflectthe movement of the controller to position bb after the contact d isdisconnected from the contact a of the controller 25. While thecontroller 25 is effecting this movement from its position ac to itsposition bb, the contact a of. the controller is connected to thecontact a a plurality of times so that the operating magnet' 19 of theprimer the contact c is disconnected from the contact a. of thecontroller so that the control relay 29 becomes deenergized and, inturn, deenergizes the operating motor 26. In position DD .01 thecontroller 25, the contact 71. is connected to the contact a of thecontroller so that the magnet 13 and the time relay 3 6, which areconnected in parallel, are simultaneously energized. The energization ofthe magnet 13 opens the air'valve 11 so that compressed air is admittedto one or more cylinders of the engine 'I to effect the startingthereof. It the engine starts immediately, its speed increases to avalue suillcient to cause the speed responsive device 30 to close itscontacts 48.

and thereby complete a circuit for the control lay 28 to effect themovement of thecontroller 25 from its position bb to its runningposition R.

Shortly after the controller 25 leaves its position bb, the contact h isdisconnected from the contact a so that the magnet 13 is deenergized andthe air valve 11 is closed. When the controller 25 reaches its runningposition R, the control relay 29 is deenergized by the disconnection ofthe contact c from the contact a of the controller 25. In the runningposition R of the controller 25 the contact i is connected to thecontact a so that an energizing circuit is com pleted for the trip coil5 of the circuit breaker 2 to effect the disconnection of thedeenergized supply circuit 3 from the distribution circuit in Theenergizing circuit of the trip coil 5 also ineludes the auxiliarycontacts 49 on the circuit breaker 2 anctthe contacts 45 01 the masterrelay 28. As soon as the circuit breaker 2 opens, a circuit is completedfor the control relay 31 to effect the energization of the closing001132 of the circuit breaker 9; The circuit of the control relay 31 isfrom one side of the control circuit through the contacts a and i of thecontroller 25, contacts 50 on the circuit breaker 2, contacts 51 on thecircuit breaker 9, winding of relay 31,

contacts 45 of the master relay 28 to the other side of the controlcircuit. Relay 31 by closing its contacts 52 completes the energizingcircuit for the closing coil 32 so that the armature winding of theunexcited generator 8 is connected to the distribution circuit 1. Assoon as the circuit breaker 9 closes its auxiliary contacts 53 completean energizing circuit for the field contact 33 so that'the field windingof the generator 8 is 1 connected across the exciter 34. This energizingThe" plant may be shut down'by opening the i control switch 39 whichdeenergizesthe master relay 28. The closing of the contacts 54 ofthemaster relay '28 completes through the contacts a and b of thecontroller 25'an energizing circuit for the control relay 29 to eiIectthe movement of the controller from the running position R to the shutdown positions. The closing of the-contacts 56 of the master relay 29completes through the auxiliary contacts 57'on the circuit breaker 9 anenergizing circuit for the trip coil 58 of the circuit breaker 9 so thatthe generator 8 is disconnected from the distribution circuit 1.

If the engine 7 fails to start when the controller 25 is in position bb,the above traced circuit for the control relay 29 through the contacts48 of the speed responsive device 30 is not completed and, therefore,the time relay 36 which is connected in'parallel with the magnet 13 ofthe air valve 11, is energized for a sufllcient length of time to efiectthe opening of its contacts 41 which are in the energizing circuit ofthe master relay 28. Relay 28, by closing its contacts 54,

completes through the contacts a and b of the tacts 40 of the voltagerelay 27 are still closed when the controller reaches its shut downpositions,-the master relay 28 is again energized to effect anotheroperation of the controller 25. If the controller 25 makes apredetermined number of revolutions within a predetermined time so thatthe notching relay 3'! is not restored to its normal position betweensuccessive operations of the controller 25, the relay 3? permanentlyopens its contacts 38 in series with the winding of the master relay-28so that when the controller subsequently reaches its shut downpositions, the master relay 28 is notagain energized to effect anotheroperation'of the controller 25 although the contacts 40 of the voltagerelay 2'? may be closed. k

While]! have, in accordance with the patent statutes, shown anddescribed my invention as applied to a particular system and asembodying various devices diagrammatically indicated, changes andmodifications will be obvious to those skilled in the art and I,therefore, aim in the appended claims to cover all such changes andmodificationsxas fall within the true spirit and scope oi my invention.

What I claim as new and desire to secure by Letters Patent of the UnitedStates, is:

connectionv '0! said supply circuit from said distribution circuit andthe subsequent connection of said plant to said distribution circuit.

2. In combination, a distribution circuit, a supply circuit connected tosaid distribution circuit, an internal combustion engine driven dynamoplant, means responsive to a predetermined condition oi. said supplycircuit for effecting the starttion of said generator for efiecting insuccession the disconnection of said supply circuit from saiddistribution circuit and the connection of said generator to saiddistribution circuit.

4. In combination, a distribution circuit, a supply circuit connected tosaid distribution circuit an internal combustion engine driven generatorhaving a field Winding, means for starting the engine driving saidgenerator, means responsive to a predetermined speed condition of saidengine for effecting in succession the disconnection of said supplycircuit from said distribution circuit and the connection of saidgenerator to said distribution circuit with the field Winding of thegenerator unexcited, and means responsive to the connection of saidgenerator to said distribution circuit for effecting the energization ofthe field winding of said generator.

5. In combination, an electric circuit, an internal combustion enginedriven generator, a cooling system for said engine means for supplyingcooling water to said cooling system, a valve controlling the supply ofcooling water, a primer, starting means, means for effecting theoperation of said valve to admit cooling water to the cooling system ofsaid engine, means responsive to the flow of water through the coolingsystem of said engine for effecting the operation of said primer and thesubsequent operation of said starting means, and means responsive to thestarting of said engine for rendering said starting means inoperativeand for effecting the connection of said generator to said circuit.

JOHN M. DRABELLE.

